The effects of chronic administration of ghrelin on rat sperm quality and membrane integrity

Abstract

AbstractAlthough ghrelin acts as a modulator of feeding behavior and energy metabolism in the central nervous system, recent studies have implicated the peripheral actions of ghrelin in reproductive tissues. Here, we investigated the effects of chronic administration of ghrelin on the motility, plasma membrane integrity and concentration of rat spermatozoa. 45-d male Wistar rats were scheduled for the study and were divided into control and treatment groups. In the treatment group, 1 nmol of ghrelin was administered as sc injection for 10 consecutive days or vehicle (physiological saline) to the control rats. Sperm collection was achieved by killing of the rats on days 15, 25 and 50 after first injection. Total sperm motility and forward progressive movement did not exhibit significant difference during the experiment, although, there was a tendency for greater motion rate on d 15 and 25 in the treated rats compared to the control group. Plasma membrane integrity (HOS-reacted spermatozoa) was significantly higher in the treated animals, especially on day 15 as well as day 25, because of possible antioxidant properties of ghrelin. This value was statistically higher on day 15 than that of day 25 (P <0.05). Likewise, there was a significant correlation between the FPM (P <0.0001, r = 0.79) and TSM (P <0.01, r = 0.52) with the HOS test percentage in the treatment group. It was not observed statistically difference in the sperm concentration between groups during all of the experimental days. In conclusion, chronic administration of ghrelin (similar to induced by energy deficiency such as fasting) increased the integrity of sperm membrane, however, the sperm motility and concentration did not display any alterations.